The Queen of the Night plant (Epiphyllum oxypetalum) is a tropical epiphyte known as a jungle cactus. It produces fragrant flowers that open for only one night. Originating from Central and South American rain forests, this plant naturally derives nutrients from decaying organic matter and rainwater, not rich soil. Therefore, specialized and careful feeding is necessary to support robust growth and its annual cycle of vegetative growth and flower production.
Choosing the Best Fertilizer Blend
During its primary growth phase, the Queen of the Night plant benefits from a balanced or low-nitrogen liquid fertilizer. A balanced NPK ratio like 10-10-10 or a slightly lower-nitrogen blend such as 5-10-10 is recommended for the growing season. High-nitrogen fertilizers encourage excessive leafy growth at the expense of flower production.
The preferred form is a water-soluble or liquid product, as this allows for easy dilution and application. A liquid feed is safer and more readily available to the roots because the plant is sensitive to salt buildup, which can occur with granular products. Fertilizers formulated for cacti or succulents work well, though a general houseplant formula can be adapted. The goal is to provide a steady, moderate supply of all macronutrients without over-stimulating stem production.
Seasonal Feeding Schedule
The timing of fertilization must align with the plant’s natural growth and dormancy cycles. Feeding should begin in early spring, typically around March, as the plant actively breaks dormancy and new growth resumes. During the active growing season (spring through late summer or early autumn), apply the diluted fertilizer solution every two to four weeks to support stem development and energy storage.
Cease all fertilization in late autumn, around October or November, as the plant enters its semi-dormant winter phase. Stopping the feed helps trigger the necessary rest period required for flower bud formation in the subsequent spring. Continuing to feed during dormancy risks disrupting this cycle and can lead to unhealthy, weak growth.
Encouraging Blooms with Phosphorus
To encourage flowering, the fertilizer blend should be manipulated in late spring or early summer, the period leading up to blooming. This is achieved by temporarily switching from the balanced feed to a high-phosphorus formulation, often called a “bloom booster.” Phosphorus, the middle number in the NPK ratio, plays a direct role in the plant’s energy transfer systems necessary for flower bud initiation and development.
A suitable high-phosphorus blend might have an NPK ratio with a significantly higher middle number, such as 2-10-10 or 3-9-4. This adjustment should be made consistently for several weeks as the plant prepares to set buds. Potassium, the third number, is also beneficial during this time, and some growers use a diluted “tomato food” to support the ongoing flowering process.
Preventing Overfeeding and Root Burn
The Queen of the Night plant is highly susceptible to damage from concentrated fertilizers, mandating a cautious application technique to prevent root burn. The most effective strategy is to fertilize “weakly, weekly.” This means the recommended dosage should be diluted to half-strength or even quarter-strength before application. This provides the plant with a steady, low dose of nutrients without the shock of a full-strength application.
Always ensure the potting medium is moist before applying any fertilizer solution, as applying it to dry roots drastically increases the risk of chemical burn. Signs of over-fertilization include a white, crusty layer on the soil surface, or browning and crisping along the edges of the flat stems. If these symptoms appear, flush the plant thoroughly with plain water to wash away excess mineral salts.